RELEVANCE OF PLATELETS IN NETS-INDUCED ENDOTHELIAL DAMAGE IN HEMOLYTIC UREMIC SYNDROME.

RODRIGUEZ RODRIGUES, N; DE CAMPOS-NEBEL, MARCELO; SCHATTNER M; LANDONI, VERÓNICA I.; CARESTIA, A; BIRNBERG-WEISS, FEDERICO; FERNANDEZ, G.C.; CASTILLO, LUIS A.; MARTIRE GRECO, DAIANA; SCHIERLOH, P.

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

SAIC, SAIB, SAI, SAA, SAB, SAFE, SAFIS, SAH, SAP

Hemolytic Uremic Syndrome (HUS) is the most common cause ofpediatric renal failure. Linked to Gram (-) Shiga toxin-producing (Stx)infections, lipopolysaccharide (LPS) and neutrophils (PMN) canpotentiate the disease. Since endothelial damage is characteristicof HUS, PMN-platelet (Plts) interaction in the context of Stx couldpromote netosis causing endothelial damage. We have shown thatStx2 increases netosis induced by LPS-treated Plts and endothelialcytotoxicity in vitro. The aim of this work is to study in detail this phenomenonand determine the relevance of netosis in a murine modelof HUS. We determined in vitro by FACS that Stx2 stimulation ofLPS-treated Plts increased the formation of PMN-Plts mixed aggregates(% CD11b+CD61+ p≤0,05) and increased the activation ofboth PMN (CD11b p≤0,05) and Plts (P-selectin p≤0,05). Additionally,the increased netosis promoted by Stx2 stimulation of LPS-treatedPlts was dependent on the PMN-Plts-mediated P-selectin junction.In order to corroborate in vitro findings, mice administrated with LPSand Stx2 showed an increased % of PMN-Plts blood aggregates(%Gr1+CD61+ p≤0.05) in LPS+Stx2 treated mice. Also the NETsin this group were increased measured using an ELISA kit (PMNElastase-DNA levels p≤0.05).Correlating with this, endothelial damagewas higher in LPS+Stx2 treated mice (von Willebrand Factor,vWF levels in plasma p≤0.05). NETs were digested and levels ofElastase-DNA decreased correlating with vWF diminution. Finally, inorder to evaluate the role of circulating Plts mice were depleted ofPlts. We observed in LPS+Stx2 mice without Plts that, both netosis(Elastase-DNA levels p≤0.05) and endothelial damage levels (vWF p≤0.05) decreased compared to LPS+Stx2. These results demonstratethe relevance of LPS+Stx2 induced netosis on vascular damageand the fundamental role of Plts in this phenomenon.